The allegations are the the manufacturer of the antibiotic did not provide adequate warnings of its potential to cause tendon injuries. There are six more bellwether cases to go. According to BNA there are approximately 1,900 Levaquin cases before Judge Higbee.

I don't have information about how the bellwether cases were picked or why eight is the number. For an analysis of how judges can do a more rigorous job of using bellwether trials to promote case resolution and equality among litigants, see my latest paper: The Case for "Trial by Formula."